Project Summary/Abstract Approximately one in eight people living with HIV in the US are unaware of their infection and the majority of adults in the US have never been HIV tested. The CDC and WHO have called for expanding HIV testing in settings where high-risk persons receive health services, including opioid treatment programs (OTPs). Persons who use opioids and other substances have high HIV risk compared with the general population; yet fewer than half of US substance use disorder (SUD) treatment programs offer on-site HIV testing and the proportion of OTPs that do has declined in the past decade. There is widespread recognition of the need for increased HIV testing and the effectiveness and economic value of on-site HIV testing in SUD treatment programs has been demonstrated. Recent recommendations from the US Preventive Services Task Force (USPSTF) that adolescents and adults should be screened for HIV in health care settings provide new opportunities for expanding access to HIV testing in OTPs. To optimize this opportunity, OTPs must address and overcome organizational-level barriers to testing, including staffing, training, concerns about delivering HIV test results and linkage to care, and the need to set up systems to support reimbursement for HIV testing services. Additionally, Hepatitis C (HCV) testing is perceived as an even greater need by some SUD programs. HCV prevalence, high among opioid users, is higher than HIV prevalence and more individuals with chronic HCV infection are unaware of their infection. Thus, we will examine whether the offer of HCV testing with HIV testing would be a motivator for adoption and implementation of HIV testing. Within this context, a 3- arm cluster-RCT of 51 OTPs will be used to test 2 active evidence-based ?practice coaching? (PC) interventions to improve the provision and sustained implementation of 1) HIV testing and linkage to care and 2) joint HIV/HCV testing and linkage to care among OTP patients. In PC, change agents and key OTP staff are provided training and support to facilitate the implementation of innovation and sustain resulting improvements. Specific aims are: Aim 1: To evaluate the effectiveness of the PC interventions on improving patient uptake of HIV testing in OTPs including the incremental impact of the HIV/HCV intervention on HIV testing. Aim 2: To examine, using mixed-methods, the impact of the PC interventions on the initiation and sustained provision of HIV testing and timely linkage to care. Aim 3: To evaluate the health outcomes, health care utilization, and cost-effectiveness of the PC interventions compared incrementally to one another and to the control condition. This will be the first study to test organizational approaches to increase HIV and HIV/HCV testing and linkage to care among patients in OTPs. This proposal is aligned with the new NIH-wide priorities for HIV/AIDS research. The first priority is to reduce HIV/AIDS incidence and one of the main points is to develop, test, and implement strategies to improve HIV testing and entry into prevention services.